1. Field of the Invention
The present invention relates to image processing apparatuses and image processing methods, and particularly relates to image processing apparatuses and image processing methods in which image data constituting objects is converted to data for output to an output device.
2. Description of the Related Art
Heretofore, color matching technologies based on color appearance models that take into account ambient light and observation conditions have been known as technologies aiming to achieve color appearance and calorimetric accordance and metamerism using ambient light and observation conditions and the like.
With these color-matching technologies, in a case where a certain document is to be observed under different observation conditions such as ambient light and background colors, it is possible to achieve accordance in the appearance of the displayed document and the printed output thereof in each of these respective observation conditions. For example, using a color appearance model such as CIECAM97s through to the subsequently improved CIECAM02, color matching can be carried out giving consideration to the appearance in a certain observation light conditions on the output side. That is, accordance in appearance can be achieved under mutually different observation conditions (for example, see Japanese Patent Laid-Open No. 2000-040140).
However, with the aforementioned conventional technologies, there is a following problem in a case where a plurality of objects of an identical color are present within a single sheet of a document even when under observation conditions that have been specified in advance.
Namely, a plurality of object images arranged within the data of a single document are influenced by the surrounding background color where the object images are arranged, thus changing the color appearance that is perceived. Examples of this are shown in FIG. 3. In FIG. 3, objects 301, 302, and 303 all have identical color values and are output as identical colors, but have respectively different background colors. Consequently, the objects 301, 302, and 303 have undesirably different color appearances due to the influence of their background colors. For example, the object 301 has a lighter background than the object 302, and therefore appears darker. And due to the gradations in the background of the object 303, the left side part of the object 303 appears darker than the right side part. It should be noted that differences in lightness according to grayscale data are illustrated in FIG. 3, but of course the same applies for chromatic color. With chromatic colors, colors even more different in hue and lightness are perceived undesirably due to an influence of chromatic adaptation for surrounding background colors.
With the aforementioned conventional technologies, it has not been possible to eliminate the influence of background color adaptation for a plurality of objects respectively having a same output color specified within a single sheet of a document and achieve accordance in appearance among these.